Collapsible carton



Feb. 18, 1958 J, COE 2,823,848

COLLAPSIBLE CARTON Filed May 31, 1956 2 Sheets-Sheet l IN V EN TOR.

United States Patent COLLAPSIBLE CARTON Merrill J. Coe, Kalamazoo, Mich., assignor to Sutherland Paper Company, Kalamazoo, Mich.

Application May 31, 1956, Serial No. 588,297

6 Claims. (Cl. 2229-39 This invention relates to a collapsible carton provided with interlocking outer closure members which may be easily and quickly engaged and are very securely held in their engaged position.

The main objects of the invention are:

First, to provide a collapsible carton which may be quickly erected to receive the contents and quickly closed, and when closed and filled with relatively heavy contents, such for example as ice cream, which sometimes is subject to severe usage, such as tumbling in freezing operations without the closure opening.

Second, to provide a carton having these advantages which is economical in the amount of stock required.

Objects relating to details and economies of the invention will appear from the description to follow. The invention is defined and pointed out in the claims.

A preferred embodiment of the invention is illustrated in the accompanying drawing, in which:

Fig. l is a perspective view of a carton embodying my invention in closed position.

Fig. 2 is a perspective view with one end of the carton closed, and the other end open to receive the contents.

Fig. 3 is a fragmentary perspective view illustrating the outer closure in partially closed position.

Fig. 4 is a plan view of the blank.

In the embodiment of my invention illustrated the carton is formed of a single cut and scored blank and comprises opposed pairs of side walls 1 and 2, and 3 and 4, respectively. These are joined by hinging score lines 5. The side wall 1 has a sealing flap 6 hingedly connected thereto at 7 which is lapped upon and secured to the outer side wall 4 at the opposite end of the blank. The sealing flap 6, in the embodiment illustrated, is provided with a pull tab 8 hingedly connected thereto by the score line 9.

The wall 2 has inner closure members 10 hingedly secured thereto at 11. These inner closure members are preferably dimensioned to fit within the erected carton and its edges in side thrust sustaining relation to the side walls. The intermediate closure members 12 are hingedly secured to the side wall 1, which is opposed to the side wall 2 when the carton is erected at 13. These intermediate closure members are adapted to lap upon and retain the inner closure member in its closed position.

The wall. 4 is provided with an outer closure member 14 hingedly secured thereto at 15, while the opposed wall 3 is provided with outer closure member 16 secured thereto at 17.

For convenience in description, the outer closure member 14 is designated as the first outer closure member and the outer closure member 16 is designated as the second outer closure member.

The first outer closure member 14 is provided with a bowed or curved slit 18 having a re-curved or hooked portion 181 at one end and a straight portion 19 at the other. This defines a flexible tab 20 having a tongue 21 at one end.

In theembodiment illustrated, the score line 22 extends from the end of the straight portion of the slit to the 2,823,848 Patented Feb. 18, 1953 adjacent edge of the shoulder member. This is for the purpose of increasing flexibility and facilitating the en gagement of the parts.

The second outer closure member 16 is provided on its swinging edge with a tab 23 having curved outer edge and provided with a slot or like slit 24 at the base thereof, which provides a tongue 25 engageable with the edge of the straight portion 19 of the slit 18, when the parts are in interlocking engagement. The closure member 16 is provided with an inwardly facing tongue 26, preferably having a curved outer edge. This tongue is desirably curved and its tip or bill extends into the base of the tab 23.

With this arrangement of parts, the sealing flap 6 at one end of the blank is secured to the outer side of the side wall 4 at the other end of the blank, and the carton may be shipped in the flat, and is quickly erected to tubular form. In use, the end closure at one end is closed, the carton filled, and the other end closed.

The inner end closure members 10, as stated, fit within the erected walls. The intermediate closure members seal the opposite side of the carton and also retain the inner closures in position. The outer closure members are then interlockingly engaged, as is illustrated in Fig. 1, one step in engagement being indicated in Fig. 3.

As outer closure members are swung inwardly, the tab 23 is inserted into the slit 18 under the flexible tab 20. Continued inward movement automatically engages the tongue 25 with the edge of the straight portion of slit 18, and practically simultaneously therewith the tongues 25 and 26 are interlockingly engaged.

These steps may be performed very quickly and easily and when the parts are engaged, they are very securely interlocked. This is important for various uses, but it is especially important in cases where the closed cartons are subjected to severe usage, for example, in some methods of freezing ice cream, the cartons are filled and then tumbled about during the freezing operation in order to secure uniform freezing.

I have illustrated and described my invention in a highly practical embodiment thereof. 1 have not attempted to illustrate or describe modifications and adaptations as it is believed this disclosure would enable those skilled in the art to embody or adapt my invention, as may be desired.

Having thus described the invention, what is claimed as new and is desired to be secured by Letters Patent is:

1. A carton of rectangular section comprising hingedly connected side walls and end closure members, each end closure comprising a rectangular inner closure member hingedly connected to one side Wall and dimensioned to close Within the other side walls With its edges in side thrust sustaining relation thereto, an intermediate closure member hingedly connected to the side wall opposite to that to which said inner closure member is connected to fold upon said inner closure member, and opposed first and second outer closure members hingedly connected to the other opposed side walls and having overlapping portions when in closed position, the first outer closure member having a transversely extending slit curved outwardly toward the free end thereof, said slit having a hooked portion at one end re'versely curving inwardly toward the hinge connection of said first closure member and a substantially straight extension at its other end, there being a flexing score line extending from the end of said straight portion to the adjacent edge of said first closure member, said slit defining a tab with a laterally projecting curved tongue at one end thereof, the second outer closure member having a tab on its swinging edge disposable through said slit in said first outer closure member, there being a laterally opening slot at the base' 3 of said tab defining a tongue engageable with the inner edge of the straight portion of the slit in said first outer closure member with the tab of the second outer closure member inserted through said slit in said first outer closure member, the second outer closure member having a hooked tongue having a curved outer edge disposed at one side of said tab thereon and facing oppositely to and interlockingly engageable with said tongue on said first outer closure member, the interengaging parts of said first and second outer closure members coacting to prevent lateral disengaging movement of the outer closure members relative to each other.

2. A carton of rectangular section comprising hingedly connected side walls and end closure members, each end closure comprising a rectangular inner closure member hingedly connected to one side wall and dimensioned to close within the other side walls with its edges in side thrust sustaining relation thereto, an intermediate closure member hingedly connected to the side wall opposite to that to which said inner closure member is connected to fold upon said inner closure member, and opposed first and second outer closure members hingedly connected to the other opposed side walls and having overlapping portions when in closed position, the first outer closure member having a transversely extending slit curved outwardly toward the free end thereof, said slit having a hooked portion at one end reversely curving inwardly toward the hinge connection of said first closure member and a substantially straight extension at its other end, said slit defining a tab with a laterally projecting tongue at one end thereof, the second outer closure member having a tab on its swinging edge disposable through said slit in said first outer closure member, there being a laterally opening slot at the base of said tab defining a tongue engageable with the inner edge of the straight portion of the slit in said first outer closure member with the tab of the second outer closure member inserted through said slit in said first outer closure memher, the second outer closure member having a tongue disposed at one side of said tab thereon and facing oppositely to and interlockingly engageable with said tongue on said first outer closure member, the interengaging parts of said first and second outer closure members coacting to prevent lateral disengaging movement of the outer closure members relative to each other.

3. A rectangular tubular carton having an end closure comprising overlapping inner closure members hingedly connected to side opposed walls and opposed first and second outer closure members hingedly connected to the other opposed side walls and having overlapping portions when in closed position, the first outer closure member having a transversely extending slit curved outwardly toward the free end thereof and terminating in an inturned reverse loop at one end and a substantially straight extension at its other end, there being a flexing score line extending from the end of said straight portion to the adjacent edge of said first closure member, said slit defining a tab with a curved outer edge portion and having a laterally projecting tongue at one end thereof, the second outer closure member having a tab on its swinging edge disposable through said slit in said first outer closure member said slit of said first closure member being of such length as to permit the tab of said second closure member to be inserted therethrough, there being a laterally opening slot at the base of said tab defining a tongue engageable with the inner edge of the straight portion of the slit in said first outer closure member with the tab of the second outer closure member inserted through said slit in said first outer closure member, the second outer closure member also having a tongue disposed at one side of said tab thereon and facing opposite ly to and interlockingly engageable with said tongue on said first outer closure member, the inter-engaging parts of said first and second outer closure members coacting 4 to prevent lateral disengaging movement of the outer closure members relative to each other.

4. A rectangular tubular carton having an end closure comprising overlapping inner closure members hingedly connected to side opposed walls and opposed first and second outer closure members hingedly connected to the other opposed side walls and having overlapping portions when in closed position, the first outer closure member having a transversely extending slit curved outwardly toward the free end thereof and terminating in an inturned reverse loop at one end and a substantially straight extension at its other end, said slit defining a tab with a curved outer edge portion and having a laterally projecting tongue at one end thereof, the second outer closure member having a tab on its swinging edge disposable through said slit in said first outer closure memher said slit of said first closure member being of such length as to permit the tab of said second closure member to be inserted therethrough, there being a laterally opening slot at the base of said tab defining a tongue engageable with the inner edge of the straight portion of the slit in said first outer closure member with the tab of the second outer closure member inserted through said slit in said first outer closure member, the second outer closure member also having a tongue disposed at one side of said tab thereon and facing oppositely to and interlockingly engageable with said tongue on said first outer closure member, the interengaging parts of said first and second outer closure members coacting to prevent lateral disengaging movement of the outer closure members relative to each other.

5. A tubular carton having an end closure comprising first and second outer closure members hingedly connected to opposed side walls, the first outer closure member having a transversely extending slit curved outwardly toward the swinging edge thereof and extended at one end thereof in a reversed portion directed toward the hinge connection of said first member defining a tab having a curved edge and a laterally projecting tongue at one end thereof, there being a flexing score line extending from the other end of said slit to the adjacent edge of said first closure member, the second outer closure member having a tab on its swinging edge disposable through said slit in said first closure member there being a laterally opening slit at the base of said tab defining a tongue engageable with the inner edge of the slit in said first outer closure member when the tab of the second outer closure member is inserted through said slit in said first outer closure member said slit of said first closure member being of such length as to permit the tab of said second closure member to be inserted therethrough, the second outer closure member having a tongue disposed at one side of said tab thereon facing oppositely to and interlockingly engageable with said tongue on said first outer closure member, the interengaging parts of said first and second outer closure members coacting to prevent lateral disengaging movement of the outer members relative to each other.

6. A tubular carton having an end closure comprising first and second outer closure members hingedly connected to opposed side walls, the first outer closure member having a transversely extending slit curved outwardly toward the swinging edge thereof and extended at one end thereof in a reversed portion directed toward the hinge connection of said first member defining a tab having a curved edge and a laterally projecting tongue at one end thereof, the second outer closure member having a tab on its swinging edge disposable through said slit in said first closure member there being a laterally opening slit at the base of saidtab defining a tongue engageable with the inner edge of the slit in said first outer closure member when the tab of the secondouter closure member is inserted through said slit in said first outer closure member said slit of said first closure member being of such length as to permit the tab of said second closure member to be inserted therethrough, the second outer closure member having a tongue disposed at one side of said tab thereon facing oppositely to and interlockingly engageable with said tongue on said first outer closure member, the interengaging parts of said first and second outer closure members coacting to prevent lateral disengaging movement of the outer members relative to each other.

References Cited in the file of this patent UNITED STATES PATENTS 

